Time-constrained control of an hvac system

ABSTRACT

An HVAC system includes an indoor unit, an outdoor unit, a thermostat, and a remote control device. The indoor unit comprises a first variable speed drive (VSD) to control a speed of HVAC rotary components within the indoor unit, and the outdoor unit comprises a second VSD to control a speed of HVAC rotary components within the outdoor unit. The thermostat in communication with the indoor unit and the outdoor unit comprises a communication interface, and a system controller in communication with the communication interface. The remote control device transmits a signal to the system controller to alter the speed of the HVAC rotary components, where the HVAC rotary components operate at a high speed mode which is above the preset speed limit of the respective HVAC rotary component to achieve an enhanced cooling mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Utility patent applicationSer. No. 15/499,833, entitled “TIME-CONSTRAINED CONTROL OF AN HVACSYSTEM” and filed Apr. 27, 2017, which claims the benefit of andpriority to U.S. Provisional Application Ser. No. 62/329,756 entitled“TIME-CONSTRAINED CONTROL OF AN HVAC SYSTEM” and filed Apr. 29, 2016,the entirety of each of which being hereby incorporated by referenceherein for all purposes.

BACKGROUND 1. Technical Field

The present disclosure relates to control systems for an air conditioneror heat pump system, and more particularly, to an HVAC controller thatcan be used to selectively control the speed of rotary equipment in theHVAC system.

2. Background of Related Art

Typically, variable speed drives (VSD) are used to control fan andcompressor speeds of an HVAC system. Conventional variable speedheating, ventilation, and air conditioning (HVAC) systems havefactory-programmed high cooling speeds which are less than the actualmaximum cooling speed the HVAC system is capable of providing. Thisprevents the system from operating at maximum speed thereby ensuringincreased component life, reliability, and lower energy consumption.Additionally, this practice matches the cooling and heating capacitiesto the requested performance specifications; to establish rated capacityand efficiency performance levels for the equipment; and to achievecompliance with industry standards such as AHRI performance auditing.

However, there are instances when a user may desire maximum coolingdespite any limitations designed into the system. For example, considera user who travels for most of the day in hot and humid weather who,upon returning home, requires the air-conditioned space to be at acomfortable temperature as soon as possible. In another scenario,consider a user who wishes to enjoy additional cooling during specialoccasions such as parties or family gatherings, during periods ofextreme heat or humidity, and so forth. An HVAC system which overcomesthe above-mentioned shortcomings would be a welcome advance in the art.

SUMMARY

An HVAC system disclosed herein is configured to control speed of HVACrotary components. The HVAC system comprises an indoor unit, an outdoorunit, a thermostat, and a remote control device. The indoor unitcomprises a first variable speed drive to control a speed of one or moreHVAC rotary components within the indoor unit, and the outdoor unitcomprises a second variable speed drive to control a speed of one ormore HVAC rotary components within the outdoor unit. The thermostat incommunication with the indoor unit and the outdoor unit, and comprises acommunication interface and a system controller. The system controlleris in communication with the communication interface to transmit asignal from a remote control device to the HVAC rotary components in theindoor unit and the outdoor unit. The remote control device is incommunication with the thermostat via a communication network, where theremote control device is configured to transmit a signal to the systemcontroller to alter the speed of one or more HVAC rotary components ofthe indoor unit and the outdoor unit, wherein one or more of the HVACrotary components are configured to operate at a high speed mode whichis above the rated speed of that HVAC rotary component to induce anenhanced (“turbo”) cooling mode in a room, and at a low speed (“quiet”)mode to reduce the noise generated from the HVAC rotary components.

In an embodiment, the HVAC rotary component of indoor unit is an indoorunit blower motor. In an embodiment, the HVAC rotary components ofoutdoor unit comprise a outdoor unit fan motor, and a compressor motor.In an embodiment, the high-speed mode to induce enhanced cooling mode inthe room is enabled for a predefined time duration after which the HVACsystem reverts to a normal operation speed. In an embodiment, when thepredefined time duration for enhanced cooling mode in the room iscompleted, a subsequent enhanced cooling mode is restricted to berestarted until the expiration of a pre-set delay time. In anembodiment, the enhanced cooling mode is canceled or disabled inresponse to a demand curtailment request received from a utility. In anembodiment, the HVAC system further comprises permitting a daily coolingbudget for the predefined time duration of the enhanced cooling mode asprescribed by the user. In an embodiment, an unused portion of the dailycooling budget is carried forward over to the corresponding day if thepredefined time duration of the enhanced cooling mode is not covered ona particular day. In an embodiment, during the low speed mode, the HVACsystem is configured to run at a lower speed than a regulated speed,which is required to maintain a minimum set point temperature. In oneembodiment, the user is able to specify how far off the minimum setpoint temperature they are willing to compromise in order to maintainlow speed mode.

In an embodiment, the thermostat further comprises a user interfaceconfigured for a user to communicate with the indoor unit and theoutdoor unit via the system controller, where the user can adjust thehigh-speed mode and the low-speed mode of the HVAC components. In anembodiment, the user is authorized to enter a range of values into theminimum set point temperature via the user interface of the thermostat.In an embodiment, the thermostat further comprises a temperature sensorconfigured to sense an ambient temperature in the room, where thetemperature sensor provides a feed to the system controller, whichtransmits the feed to the indoor unit to alter the speed of the indoorblower motor. In an embodiment, the outdoor unit further comprises a lowspeed mode user interface configured for a user to directly access thelow speed mode user interface from outdoors, where the user can directlyset the HVAC rotary components at low speed mode. In an embodiment, thelow speed mode user interface is configured to restrict access to thelow speed mode to an authorized user.

In another aspect, a method of controlling the speed of HVAC rotarycomponents is disclosed. In an exemplary embodiment, the method includesproviding an HVAC system comprising an indoor unit, an outdoor unit, athermostat, and a remote control device. A signal from the remotecontrol device is transmitted via the system controller to one or moreHVAC rotary components in the indoor unit and the outdoor unit, and thespeed of the HVAC rotary components of the indoor unit and the outdoorunit is altered by receiving the transmitted signal from the remotecontrol device. The HVAC rotary components are operated at a high-speedmode, which is above the rated speed of that HVAC rotary component toinduce an enhanced cooling mode in a room, and the HVAC rotarycomponents are operated at a low speed mode to reduce the noisegenerated from the HVAC rotary components.

Other features and advantages will become apparent from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the disclosed system and method are describedherein with reference to the accompanying drawings, which form a part ofthis disclosure, wherein:

FIG. 1 is a schematic diagram of an HVAC system in accordance with anembodiment of the present disclosure;

FIGS. 2A-2D illustrate a user interface of a thermostat of an HVACsystem in accordance with an embodiment of the present disclosure;

FIGS. 3A-3B illustrate methods to control speed of HVAC rotarycomponents in accordance with an embodiment of the present disclosure;and

FIGS. 4A-4D illustrate flowcharts describing a time-constrainedoperating mode of the HVAC system, time availability for an enhancedcooling mode, demand curtailment check, and max mode of operation inaccordance with embodiments of the present disclosure.

The various aspects of the present disclosure mentioned above aredescribed in further detail with reference to the aforementioned figuresand the following detailed description of exemplary embodiments.

DETAILED DESCRIPTION

The present disclosure is directed to an HVAC system havingtime-constrained selective speed control of HVAC rotary components suchas a fan, a compressor motor, and/or a blower. In an embodiment, theHVAC system includes an indoor unit, an outdoor unit, a thermostat, anda remote control device. The indoor unit of the conventional HVAC systemincludes a first variable speed drive (VSD) to control a speed of theHVAC rotary components in the indoor unit. The outdoor unit includes asecond variable speed drive to control a speed of the HVAC rotarycomponents in the outdoor unit. The thermostat is in communication withthe indoor unit and the outdoor unit, and contains a communicationinterface and a system controller.

The system controller is in communication with the communicationinterface to convey a signal from a remote control device to the HVACrotary components in the indoor unit and the outdoor unit. The remotecontrol device is in remote contact with the thermostat via acommunication network, where the remote control device transmits asignal to the system controller to modify the speed of the HVAC rotarycomponents of the indoor unit and the outdoor unit, where one or more ofthe HVAC rotary components operate at a high speed mode which is abovethe rated speed of that HVAC rotary component to induce an enhancedcooling mode in a room, and at a low speed mode to reduce the noisegenerated from the HVAC rotary components.

Particular illustrative embodiments of the present disclosure aredescribed herein below with reference to the accompanying drawings;however, the disclosed embodiments are merely examples of thedisclosure, which may be embodied in various forms. Well-known functionsor constructions and repetitive matter are not described in detail toavoid obscuring the present disclosure in unnecessary or redundantdetail. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present disclosure in virtually anyappropriately detailed structure. In this description, as well as in thedrawings, like-referenced numbers represent elements, which may performthe same, similar, or equivalent functions. The word “exemplary” is usedherein to mean “serving as an example, instance, or illustration.” Anyembodiment described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other embodiments. The word“example” may be used interchangeably with the term “exemplary.”

Referring to FIG. 1, an HVAC system 100 is configured to control speedof HVAC rotary components. The HVAC system 100 comprises an indoor unit101, an outdoor unit 103, a thermostat 105, and a remote control device108. The indoor unit 101 comprises a first variable speed drive 102 tocontrol a speed of one or more HVAC rotary components within the indoorunit 101, and the outdoor unit 103 comprises a second variable speeddrive 104 to control a speed of one or more HVAC rotary componentswithin the outdoor unit 103. As used herein, a “variable-speed drive”(VSD) refers to equipment used to control the rotational speed of anelectric motor.

Several basic types of VSDs are in current use depending on motorapplication. For example, a variable frequency drive (VFD) controls thespeed of an AC induction motor by varying the motor's supplied voltageand frequency of power. Other VSD designs commonly used today includepulse width modulation (PWM), current source inverter (CSI), voltagesource inverter (VSI) designs, and stepped multiple-speed designs. ThePWM drive is widely used in HVAC systems because it is highly reliable,cost-effective, reflects the least amount of harmonics back into itspower source, and works well with motors ranging in size from about ½horsepower (hp) to 500 hp. Some VSD designs provide for infinitelyvariable speed adjustment of motor speed, while others, sometimesreferred to as “multiple speed drives,” provide a finite number ofdiscrete motor speeds (e.g., low-medium-high). Embodiments of thepresent disclosure may be utilized with any VSD design.

As further shown in FIG. 1, the thermostat 105 is in communication withthe indoor unit 101 and the outdoor unit 103, and comprises acommunication interface 106 and a system controller 107. The systemcontroller 107 is in communication with the communication interface 106to transmit a signal from a remote control device 108 to the HVAC rotarycomponents in the indoor unit 101 and the outdoor unit 103. The remotecontrol device 108, for example, a smart phone or a cloud service, is incommunication with the thermostat 105 via a communication network 109,where the remote control device 108 is configured to transmit a signalto the system controller 107 to alter the speed of one or more HVACrotary components of the indoor unit 101 and the outdoor unit 103 viathe first variable speed drive 102 and/or the second variable speeddrive 104, where the HVAC rotary components operate at a high speedmode, or a boost mode, which is above the rated speed of that HVACrotary component to induce an enhanced cooling mode in a room, and at alow speed mode, or a quiet mode, to reduce the noise generated from theHVAC rotary components. In an embodiment, the thermostat 105 furthercomprises a user interface 113 configured for a user to communicate withthe indoor unit 101 and the outdoor unit 103 via the system controller107, where the user can adjust the high speed mode and the low speedmode of the HVAC components (FIGS. 2A-2D). The user may activate theenhanced cooling mode feature manually through the user interface 113 ofthe thermostat 105, or through a smart phone app 108 b that communicateswith the thermostat 105 either through a direct or peer-to-peerconnection, or through a cloud-based service 108 a. The quiet modefeature may be activated in the same manner.

In an embodiment, the HVAC rotary component of indoor unit 101 includesan indoor blower motor 110. In an embodiment, the HVAC rotary componentsof outdoor unit 103 include an outdoor fan motor 111 and a compressormotor 112. In an embodiment, the high-speed mode or boost mode to induceenhanced cooling mode in the room is enabled for a predefined timeduration after which the HVAC system 100 reverts to a normal operationspeed. The boost mode is only operated for a stipulated time in order toavoid prolonged excessive loads or energy consumption of the equipmentbecause of continuous operation above the rated speed of operation. Thatis, enhanced cooling mode is enabled only for a pre-specified timeduration, for example and without limitation, 30 minutes, before thesystem reverts to normal operation. Thus, all performance rating datashould remain unchanged as well as system operation for performanceaudit testing of the HVAC system 100. In an embodiment, the outdoor unit103 further comprises a quiet mode user interface 115 configured for auser to directly access the low speed mode user interface 115 fromoutdoors, where the user can directly set the HVAC rotary components atquiet mode. Here, an outdoor user can activate the quiet mode by simplywalking up to the outdoor unit 103 and pressing a quiet button. In anembodiment, activating the quiet mode function at the outdoor unit 103comprises the user entering a security code or password into the lowspeed mode user interface 115 to authenticate the user, which avoidsunwanted activation of the quiet mode.

Referring to FIGS. 2A-2D, an example embodiment of a user interface 113of the thermostat 105 of HVAC system 100 is illustrated. In the exampleembodiment, the user is authorized to enter a range of values into thetemperature setting control 201 where the user can set the desiredtemperature during boost mode or quiet mode. In one embodiment, the useris able to specify how far off the set point temperature they arewilling to compromise in order to maintain low speed mode. Thermostat105 further comprises a temperature display 114 configured to displaythe sensed ambient temperature in the room. The sensed temperature isprovided to the system controller 107 which, in turn, transmits acontrol signal to the indoor unit 101 to alter the speed of the indoorblower motor 110. As shown in FIGS. 2A-2C, user interface 113 includesenhanced mode control 202 and quiet mode control 203. Enhanced modecontrol 202 incorporates a display element 202 a which indicates thecurrent enhanced mode status. For example, in FIG. 2A display element202 a shows the time remaining for the boost mode or the enhanced coolmode to finish, for example, 28 minutes and 51 seconds. In FIG. 2B,display element 202 a shows the next available set time for boost modeto be activated again, and in FIG. 2C, display element 202 a indicatesthe unavailability of boost mode due to demand curtailment from theelectric utility 116.

Referring to FIG. 2D, which shows a UI for the max cool mode whichincludes max mode control 204. Max mode operates similarly to enhancedmode, but without any limitations such as, for example, no limited timeof operation, no daily budgeted mode of operation, or no restrictionsdue to a demand curtailment request. This mode enables the user tooverride the preprogrammed HVAC system 100 limit whenever and for aslong as the user wishes. In an example, variable speed thermostats rampthe system speed up and down. This ramp can take time depending on themeasured temperature in the environment. A user may get frustrated withhow slowly the variable speed system ramps up when there is an immediateneed for maximum cooling. Max mode control 204 switches HVAC system 100into maximum speed with no ramp time. Max mode may remain in effectuntil the max mode control 204 is pressed again to cancel max mode. Insome embodiments, max mode may be canceled after a user-selectablepredetermined period of time has elapsed, and/or re-activated at anytime.

In an embodiment, when the predefined time duration for enhanced coolingmode in the room is completed, a subsequent enhanced cooling mode isrestricted from restarting or re-initiated until the expiration of apre-set delay time, for example and without limitation, about 8 hours.In an embodiment, the enhanced cooling mode is canceled or disabled inresponse to a demand curtailment request received from an electricutility 116. In an embodiment, the HVAC system 100 comprises a dailycooling budget of a predefined time duration of the enhanced coolingmode. In one non-limiting example, a maximum of 90 minutes of enhancedcooling is permitted per day to be used as desired. In an embodiment, anunused portion of the daily cooling budget is carried forward over tothe corresponding day if the predefined time duration of the enhancedcooling mode is not used on a particular day. In an embodiment, theunused portion available to be carried over cannot exceed one day'sallocation time. This ensures a user cannot bank essentially limitlessenhanced time during, for example, off seasons when cooling is notrequired.

The thermostat 105 includes the user interface 113 to provide access toboost mode and amount of boost mode time remaining. In anotherembodiment, the system controller 107 maintains boost mode parametersand communicates boost mode status to the thermostat 105. In anotherembodiment, the thermostat 105 maintains boost mode status, such as,time remaining. The system controller 107 and/or thermostat 105 may bein communication with the local electric company to receive a demandcurtailment request and inhibit boost mode in accordance with the demandcurtailment event. The boost mode parameters, for example, time limits,daily maximums etc., are stored in an unmodifiable memory, that is,factory-set, no user access (or user read-only access), encrypted,and/or permanent. In some embodiments, boost mode parameters may bemodifiable only by authorized service personnel.

In an embodiment, a quiet “low speed” mode is provided in which the HVACsystem 100 is configured to run at a lower speed than that is requiredto maintain a minimum set point temperature. Since conventional systemshave fans which may operate continuously, quiet mode enables the user toenjoy a quieter environment, for example, to reduce noise from theoutdoor unit during outdoor parties, barbeques, or to reduce indoornoise during teleconferences or recording sessions, and the like. In anembodiment, quiet mode allows the user to specify a maximum allowabletemperature offset from the set point, for example, about 4 degreeswarmer than set point in order to enable the system to run at a slowerquieter speed than normal. There is no limit on the number of timesquiet mode may be invoked, although the user may optionally specify atime limit for quiet mode cycle. When maximum temperature offset isreached, the system controller 107 increases speed only as much asneeded to maintain the offset temperature. In some embodiments, quietmode may be invoked in accordance with a schedule to accommodaterecurring events as child nap times, study periods, and/or to complywith local sound level regulations.

Turning now to FIG. 3A, a method 300 of controlling a high-speed mode ofHVAC rotary components in accordance with an embodiment of the presentdisclosure is shown. The method to control high speed mode of HVACrotary components 300 includes providing 301 an HVAC system 100 havingan indoor unit 101, an outdoor unit 103, a thermostat 105, and a remotecontrol device 108. A signal from thermostat 105 and/or remote controldevice 108 is transmitted 302 via the system controller 107 to one ormore HVAC rotary components in the indoor unit 101 and the outdoor unit103, and the speed of the HVAC rotary components of the indoor unit 101and the outdoor unit 103 is altered 303 in response to receiving thetransmitted signal from the remote control device 108. The HVAC rotarycomponents are operated 304 at a high-speed mode, which is above therated speed of that HVAC rotary component to induce an enhanced coolingmode in a room.

In embodiments, use of remote control device 108 is optional, andembodiments are contemplated which utilize a thermostat or controllerprovided by indoor unit 101. In embodiments, the HVAC rotary componentsare controlled from a remote server or a cloud-based service.

Referring to FIG. 3B, a method 310 of controlling a low speed mode ofHVAC rotary components in accordance with an embodiment of the presentdisclosure is shown. The disclosed method to control low speed mode ofHVAC rotary components 310 includes providing 311 an HVAC system 100having an indoor unit 101, an outdoor unit 103, a thermostat 105, and aremote control device 108. A signal from thermostat 105 and/or remotecontrol device 108 is transferred 312 via the system controller 107 tothe HVAC rotary components in the indoor unit 101 and the outdoor unit103, and the speed of the HVAC rotary components of the indoor unit 101and the outdoor unit 103 is changed 313 by accepting the transferredsignal from the remote control device 108. The HVAC rotary componentsare actuated 314 at a low speed mode to reduce the noise generated fromthe HVAC rotary components.

Referring now to FIGS. 4A-4D, which illustrate embodiments describingtime constrained operation of the HVAC system, time availability forenhanced cooling mode, demand curtailment check, and max mode ofoperation. As shown in FIG. 4A and in FIG. 2A, the user starts 401 andinitiates the enhanced cooling mode 402 of the HVAC system 100. Then, asdiscussed above with reference to FIGS. 2A-2D, the remaining time limit403 for the enhanced cooling mode to finish is checked. If the timelimit has not expired, i.e., it has not finished, then the HVAC system100 remains 404 in enhanced cooling mode. If the predefined time limit403 has expired, then enhanced mode is ended 405 and the system returnsto normal speed (i.e., the normal high speed limit is again imposed) andthe HVAC system 100 restricts 406 entry into a subsequent enhancedcooling mode. In the example embodiment shown, enhanced mode isrestricted for a predetermined period of time (e.g., 8 hours).

As shown in FIG. 4B and in FIG. 2B, the user starts 407 and initiates402 enhanced cooling mode. Then the system checks 408 if the predefineddaily cooling budget, for example, 90 minutes, is completed or not. Ifit is not completed, then the HVAC system 100 retains 409 enhancedcooling mode within the remaining daily cooling budget, however, if thepredefined daily cooling budget is completed, then the HVAC system 100exits enhanced mode 410 and restricts 411 subsequent enhanced coolingmode until the next day.

With reference now to FIG. 4C, and with continued reference to FIG. 4Aand FIG. 2C, the predefined time limit 403 for the enhanced cooling modeto finish is checked. If it has not finished then the HVAC system 100can remain 404 in enhanced cooling mode. If the predefined time limit403 is finished, then the HVAC system 100 restricts 405 activation of asubsequent enhanced cooling mode in accordance with the desired strategy(e.g., enhanced re-activation wait time, daily budget, etc.). Here,after retaining 404 the enhanced cooling mode, if the desired coolinglimit is reached 417, then the quiet mode may be activated 418. If thedesired cooling limit is not reached 417, then the HVAC system 100 againremains 404 in enhanced cooling mode. Now, after the HVAC system 100restricts 405 the subsequent enhanced cooling mode, if the enhanced coolmode is again initiated 412 before the next available time for enhancedcool mode, a demand curtailment check 413 is performed, and if thedemand curtailment request is not received from the utility 116provider, the enhanced cooling mode is activated 419 before nextavailable time. On the other hand, if the demand curtailment request isreceived, then the enhanced cooling mode before next available time isrestricted 415 by the HVAC system 100.

As shown in FIG. 4D, the user starts 401 by calling for additionalcooling 420. If limitations are active, then the enhanced cooling modeis initiated 422 as described with reference to FIGS. 4A-4C. Iflimitations do not exist then max mode may be activated 421. The maxmode is a modified version of the enhanced cool or boost mode 202, butwithout any limitations such as, for example, a stipulated time ofoperation such as 90 minutes with a regulated initiation time, a dailycooling budgeted mode of operation, or restrictions due to response todemand curtailment. After activating 421 the max mode, a demandcurtailment check 423 is performed. If a demand curtailment is ineffect, then max cooling mode is restricted (e.g., canceled ordisallowed from activation). Conversely, if no demand curtailment is ineffect, max cooling mode may continue without limitations 425 until suchtime max mode is terminated 426.

ASPECTS

It is noted that any of aspects 1-14 and 15-20 may be combined with anyother in any combination.

Aspect 1. An HVAC system configured to control speed of HVAC rotarycomponents, the HVAC system comprising an indoor unit comprising a firstvariable speed drive to control a speed of an indoor unit rotarycomponent, the first variable speed drive including a speed limit thatis below the maximum speed of the indoor unit rotary component; anoutdoor unit comprising a second variable speed drive to control a speedof an outdoor unit rotary component, the second variable speed driveincluding a speed limit that is below the maximum speed of the outdoorunit rotary component; a thermostat in communication with the indoorunit and the outdoor unit, the thermostat configured to transmit a firstcontrol signal to the first variable speed drive and the second variablespeed drive; wherein upon receiving the first control signal, the firstvariable speed drive and the second variable speed drive are configuredto operate in a high speed mode which is above the speed limit of therespective rotary component thereof.

Aspect 2. The HVAC system in accordance with aspect 1, wherein thethermostat is further configured to transmit a second control signal tothe first variable speed drive and the second variable speed drive,wherein upon receiving the second control signal, the first variablespeed drive and the second variable speed drive are configured tooperate in a low speed mode.

Aspect 3. The HVAC system in accordance with any of aspects 1-2, whereinthe indoor unit rotary component comprises an indoor blower motor.

Aspect 4. The HVAC system in accordance with any of aspects 1-3, whereinthe outdoor unit rotary component is selected from the group consistingof an outdoor fan motor and a compressor motor.

Aspect 5. The HVAC system in accordance with any of aspects 1-4, whereinthe high speed mode is enabled for a predetermined time duration afterwhich the HVAC system reverts to a normal speed mode.

Aspect 6. The HVAC system in accordance with any of aspects 1-5, whereinwhen the predefined time duration for enhanced cooling mode in the roomis completed, a subsequent enhanced cooling mode is restricted fromrestarting until the expiration of a pre-set delay time.

Aspect 7. The HVAC system in accordance with any of aspects 1-6, whereinthe enhanced cooling mode is canceled and/or disabled in response to ademand curtailment request received from a utility.

Aspect 8. The HVAC system in accordance with any of aspects 1-7, furthercomprising providing a predefined daily time budget for the enhancedcooling mode.

Aspect 9. The HVAC system in accordance with any of aspects 1-8, whereinan unused portion of the daily time budget is carried forward over tothe following day.

Aspect 10. The HVAC system in accordance with any of aspects 1-9,wherein during the low speed mode, the HVAC system is configured to runat a lower speed than that which is required to maintain a minimum setpoint temperature.

Aspect 11. The HVAC system in accordance with any of aspects 1-10,wherein the thermostat further comprises a system controller; and a userinterface configured for a user to communicate with the indoor unit andthe outdoor unit via the system controller, wherein the user caninitiate the high speed mode and/or the low speed mode of the HVACcomponents.

Aspect 12. The HVAC system in accordance with any of aspects 1-11,wherein the user interface is configured to facilitate entry of amaximum allowable deviation from a set point temperature.

Aspect 13. The HVAC system in accordance with any of aspects 1-12,wherein the outdoor unit further comprises a low speed mode userinterface to enable a user to access the low speed mode at the outdoorunit.

Aspect 14. The HVAC system in accordance with any of aspects 1-13,wherein the low speed mode user interface is configured to restrictaccess to the low speed mode to an authorized user.

Aspect 15. A method to control speed of HVAC rotary components,comprising: providing an HVAC system comprising an indoor unitcomprising a first variable speed drive to control a speed on an indoorunit rotary component, the first variable speed drive including a speedlimit that is below the maximum speed of the indoor unit rotarycomponent; an outdoor unit comprising a second variable speed drive tocontrol a speed of an outdoor unit rotary component, the second variablespeed drive including a speed limit that is below the maximum speed ofthe outdoor unit rotary component; a thermostat in communication withthe indoor unit and the outdoor unit, the thermostat configured totransmit a first control signal to the first variable speed drive andthe second variable speed drive; and transmitting the first controlsignal to the indoor unit rotary component and the outdoor unit outdoorunit rotary component to operate said rotary components at a high speedmode which is above the speed limit of said rotary components toeffectuate an enhanced cooling mode.

Aspect 16. The method in accordance with aspect 15, further comprisingoperating the rotary components at a low speed mode to reduce the noisegenerated from the rotary components.

Aspect 17. The method in accordance with any of aspects 15-16, furthercomprising operating the rotary components at a lower speed than thatwhich is required to maintain a set point temperature.

Aspect 18. The method in accordance with any of aspects 15-17, whereininducing an enhanced cooling mode includes enabling the high speed modefor a predefined time duration after which the HVAC system reverts backto a normal operation speed.

Aspect 19. The method in accordance with any of aspects 15-18, furthercomprising restricting a subsequent enhanced cooling mode to berestarted until the expiration of a pre-set delay time.

Aspect 20. The method in accordance with any of aspects 15-19, furthercomprising canceling and/or disabling the enhanced cooling mode inresponse to a demand curtailment request received from a utility.

Particular embodiments of the present disclosure have been describedherein, however, it is to be understood that the disclosed embodimentsare merely examples of the disclosure, which may be embodied in variousforms. Well-known functions or constructions are not described in detailto avoid obscuring the present disclosure in unnecessary detail.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a basis for theclaims and as a representative basis for teaching one skilled in the artto variously employ the present disclosure in any appropriately detailedstructure.

What is claimed is:
 1. A heating, ventilation, and air conditioning(HVAC) system, comprising: an indoor unit comprising a first variablespeed drive to control a speed of an indoor unit rotary component, thefirst variable speed drive including a speed limit that is below amaximum speed of the indoor unit rotary component; an outdoor unitcomprising a second variable speed drive to control a speed of anoutdoor unit rotary component, the second variable speed drive includinga speed limit that is below a maximum speed of the outdoor unit rotarycomponent; a system controller in communication with the indoor unit andthe outdoor unit and configured to transmit a first control signal tothe first variable speed drive and the second variable speed drive;wherein upon receiving the first control signal, the first variablespeed drive and the second variable speed drive are configured tooperate in a high speed mode which is above the speed limit of therespective rotary component thereof.
 2. The HVAC system in accordancewith claim 1, further comprising a temperature sensor in communicationwith the system controller and configured to sense an ambienttemperature in a conditioned space.
 3. The HVAC system in accordancewith claim 1, wherein the system controller is further configured totransmit a second control signal to the first variable speed drive andthe second variable speed drive, wherein upon receiving the secondcontrol signal, the first variable speed drive and the second variablespeed drive are configured to operate in a low speed mode.
 4. The HVACsystem in accordance with claim 1, wherein the indoor unit rotarycomponent comprises an indoor blower motor.
 5. The HVAC system inaccordance with claim 1, wherein the outdoor unit rotary component isselected from the group consisting of an outdoor fan motor and acompressor motor.
 6. The HVAC system in accordance with claim 1, whereinthe high speed mode is enabled for a predetermined time duration toeffectuate an enhanced cooling mode after which the HVAC system revertsto a normal speed mode.
 7. The HVAC system in accordance with claim 6,wherein when the predefined time duration for enhanced cooling mode inthe room is completed, a subsequent enhanced cooling mode is restrictedfrom restarting until the expiration of a pre-set delay time.
 8. TheHVAC system in accordance with claim 6, wherein the enhanced coolingmode is canceled and/or disabled in response to a demand curtailmentrequest received from a utility.
 9. The HVAC system in accordance withclaim 6, further comprising providing a predefined daily time budget forthe enhanced cooling mode.
 10. The HVAC system in accordance with claim9, wherein an unused portion of the daily time budget is carried forwardover to the following day.
 11. The HVAC system in accordance with claim9, wherein during the low speed mode, the HVAC system is configured torun at a lower speed than that which is required to maintain a minimumset point temperature.
 12. The HVAC system in accordance with claim 1,further comprising a user interface in communication with the systemcontroller and configured for a user to communicate with the indoor unitand the outdoor unit via the system controller, wherein the user caninitiate the high speed mode and/or the low speed mode of the HVACcomponents.
 13. The HVAC system in accordance with claim 12, wherein theuser interface is configured to facilitate entry of a maximum allowabledeviation from a set point temperature.
 14. The HVAC system inaccordance with claim 1, wherein the outdoor unit further comprises alow speed mode user interface to enable a user to access the low speedmode at the outdoor unit.
 15. The HVAC system in accordance with claim14, wherein the low speed mode user interface is configured to restrictaccess to the low speed mode to an authorized user.
 16. A method tocontrol speed of heating, ventilation, and air conditioning (HVAC)rotary components, comprising; providing a HVAC system comprising: anindoor unit comprising a first variable speed drive to control a speedon an indoor unit rotary component, the first variable speed driveincluding a speed limit that is below a maximum speed of the indoor unitrotary component; an outdoor unit comprising a second variable speeddrive to control a speed of an outdoor unit rotary component, the secondvariable speed drive including a speed limit that is below a maximumspeed of the outdoor unit rotary component; a system controller incommunication with the indoor unit and the outdoor unit and configuredto transmit a first control signal to the first variable speed drive andthe second variable speed drive; and transmitting the first controlsignal to the indoor unit rotary component and the outdoor unit outdoorunit rotary component to operate said rotary components at a high speedmode which is above the speed limit of said rotary components toeffectuate an enhanced cooling mode.
 17. The method in accordance withclaim 16, wherein providing a HVAC system includes providing atemperature sensor configured to sense an ambient temperature in aconditioned space.
 18. The method in accordance with claim 16, furthercomprising operating the rotary components at a low speed mode to reducethe noise generated from the rotary components.
 19. The method inaccordance with claim 18, further comprising operating the rotarycomponents at a lower speed than that which is required to maintain aset point temperature.
 20. The method in accordance with claim 16,wherein inducing the enhanced cooling mode includes enabling the highspeed mode for a predefined time duration after which the HVAC systemreverts back to a normal operation speed.
 21. The method in accordancewith claim 17, further comprising restricting a subsequent enhancedcooling mode to be restarted until the expiration of a pre-set delaytime.
 22. The method in accordance with claim 16, further comprisingcanceling and/or disabling the enhanced cooling mode in response to ademand curtailment request received from a utility.